Tobacco Settlement Grant Funds Research on Adolescent Drug Use

Posted: July 26, 2005 at 1:00 am, Last Updated: November 30, -0001 at 12:00 am

By Stephanie Hay

Bob Smith
Bob Smith
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Bob Smith, chair of the Department of Psychology, and Karl Fryxell, professor in the Department of Molecular and Microbiology, recently received an additional $440,000 from the Virginia Tobacco Settlement Foundation to fund their research, now in its fourth year, on adolescent drug use.

The study was originally funded to evaluate potential permanent changes resulting from adolescent use of nicotine and compare those with changes resulting from the consumption of alcohol and cocaine.

Smith reviewed literature that found adolescent brain development is susceptible to drug-induced changes. Fryxell is examining gene expression changes induced by drug dosing, which, Smith says, may underlie the lasting functional changes.

Major findings of the study include the following:

  • Adolescent nicotine use results in persisting changes in the structure of brain cells involved in addiction and behavioral changes indicative of stronger addiction.
  • Both adolescent nicotine and adolescent alcohol use produce exaggerated negative emotions in adults. Negative emotions also contribute to addiction in humans.
  • Significant gene expression changes occur during nicotine dosing. These are age related (early adolescence is more susceptible), and some specific changes may tie into growth of neurons and negative emotional effects of nicotine.
  • In collaboration with Susan Bachus, Department of Psychology and Krasnow Institute for Advanced Study, the team has shown that adolescent nicotine induces permanent changes in some aspects of brain chemistry. These are probably related to addictive changes.
  • Work in progress indicates strongly that early adolescence is a more sensitive period than late adolescence.

“Adolescent nicotine consumption causes changes in gene expression, which alter the normal cascade of brain development. These developmental changes permanently alter brain structure, brain chemistry, and brain function,” Smith says. “The functional changes include increased susceptibility to addiction to any abused drug, negative emotional changes that may reinforce the addiction liability, and changes in cognition, judgment, and decision making.

“Our work with animals suggests that developmental sensitivity to these lasting, negative effects is probably greatest near and prior to puberty, indicating that efforts to prevent smoking and drug abuse around this age may have the greatest positive impact on children.”

This article originally appeared in a slightly different format in CAS Connection, July 15, 2005.

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